Plentiful harvest of Oates

The most versatile and prolific of American novelists, she has produced something like 50 novels (if you count her pseudonymous works as Rosamund Smith and Lauren Kelly), a dozen novellas, 19 short story collections, a wheen of intellectually rigorous essays and criticism, half a dozen poetry collections, children's books, numerous plays and non-fiction works, and the libretto for an opera.

Oates dismisses with an elegant shrug of her frail shoulders the notion that she's slugging it out with her friends Mailer, Updike and Roth for the title of Great American Novelist. Yet her friend, the novelist and biographer Edmund White, insists that she is intensely competitive, although reluctant to admit it. "She is a truly great writer, so of course she ranks with those guys. She's very much their equal, a fine writer and a potential Nobel laureate," he says, agreeing that she suffers from the prodigious author syndrome in the States - if she can crank out that much, she can't be that good. "But she is that good."

She writes so much anyway, adds White, because she never wastes a moment, despite the fact that she and her self-effacing husband, the academic and publisher Raymond J Smith, regularly throw dinner parties for friends, who range from the movie star and writer Steve Martin to designer Gloria Vanderbilt, at their wood and glass home in the New Jersey countryside. And, of course, adds White, she's a wonderful cook, too.

White's office at Princeton, where he also teaches creative writing, is across the corridor from Oates's room, which is painted in austere shades of grey. Today, the college's Distinguished Professor of Humanities is stylishly dressed in scarlet, a colour almost shocking in its vibrancy against her pale complexion.

The woollen blouse, fastened to the throat with a row of pearly buttons, was made for the award-winning writer by her late and much-mourned mother, Carolina, who died two years ago at the age of 87.

Her mother, to whom she was close, was a homemaker in the 1950s mould: she baked bread, sewed, and created exquisite little arts and crafts objects, many of which decorate Oates's art-filled home. Like Gwen Eaton, the widowed mother of the heroine of Oates's latest novel, Mother, Missing - Carolina Oates was a good woman, sweet-natured and generous to a fault.

It's those housewifely qualities that Oates set out to celebrate in this book, despite the fact that Gwen is brutally murdered. This is, says Oates, the one book she has written for her mother. It's therefore the most deeply personal of her novels, although she has long maintained that she's an elective writer - choosing to tell other people's stories, not her own.

"My mother did not die as a result of a random act of violence," she says. "She had been ill for some time. Yet, I believe that all deaths are acts of violence. The loved one is cruelly snatched away from you - and death is always brutal. Suddenly, you are robbed of someone you love. I think that is why I wanted to celebrate my mother's life. Housewives, ordinary women like her, are disregarded nowadays.

"Anyone who knew my mother will recognise her in Gwen," explains Oates wistfully, adding that as her narrator - Gwen's daughter, Nikki - was writing about clearing out the clothes in her dead mother's attic, Oates was emptying her own mother's wardrobes, also assailed by grief.

The novel is an unsparing portrayal of the horror of losing a parent and the tumult of sorrow that death brings in its wake. It begins with a chilling promise: "This is my story of missing my mother. One day, in a way unique to you, it will be your story, too."

And that is Oates's great gift - the ability to convince us that we are reading about ourselves in novel after novel after novel. Yet America's leading lady of letters airily dismisses the idea that her output is extraordinary. With a languid wave of one of her hands, in which she then thoughtfully cups her small face, she claims that she doesn't write any more than many other people, citing Stephen King, or Dickens, or Updike.

While her husband - they met in 1961 and married after a three-month courtship - edits their literary magazine, the prestigious Ontario Review, she is its associate editor. She writes in longhand, sometimes for up to ten hours a day when she's finishing a book because she wants to find out how it will end, Oates says in her still, small voice - although she never begins a novel without knowing what the last line will be.

In Mother, Missing, it is: "In this way ended my first full year of missing Mom." She had this sentence before she knew what story she would eventually tell. Nevertheless, the birdlike Oates - she has frizzy brown hair that fizzes around her head like so many subversive thoughts, and yearning, heavy-lidded amber eyes - has a genius for inventing page-turning plots written with immense generosity of spirit. Oates's heart, you sense, is easily as huge as her mind.

With her somewhat fey, rather melancholic manner, Oates comes across as a gentle woman, quietly composed and an absolute pleasure to talk to, whether discussing her beloved cats or the works of Lewis Carroll. She read Carroll when she was eight, then committed every word to memory. "My heart leapt when I read Alice - I started writing because I wanted to continue that book."

A country girl, she was raised among poor Irish Catholic farmers, in Millersport, New York, on her grandparents' farm. Her father Frederic - often the model for the richly characterised, protective, working-class men in her novels - was a factory worker who read Dickens and scrabbled to make ends meet. Oates has a younger brother, Fred Jnr, and a sister, Lynn Ann, who is severely autistic.

The landscape of her childhood was wild. There were abandoned houses to explore - "forbidden properties of all kinds" - and secret places in which to hide. Small wonder that so many of her novels fall into the genre of domestic Gothic, although Oates has also made the cinematic psychological thriller and the lyrical novella very much her own. Few contemporary novelists have written so empathetically about America's underclass. She is truly the poet of the proletariat, endowing the blue-collar workers of her own roots with dignity and complexity.

She speaks fondly of her parents. Her father, who eventually went to university in the late 1980s, died of cancer in 2000. The family was not cultured, although she was named for James Joyce - she was born in 1938 on Bloomsday, 16 June, the date Leopold Bloom traverses Dublin in Ulysses. She looks back on her bookish childhood with nostalgia and affection, although her family history reads like the plot of one of her novels.

"It is surprisingly violent," she agrees when I quote back to her a remark she once made that her life had been "shaped by violent acts". Her paternal great-grandfather attacked his wife with a hammer, then shot himself. Her maternal grandfather, a Hungarian immigrant, died in a brawl, leaving nine children.

Desperately poor, his widow "gave away" her baby daughter, Carolina. Oates's mother remained traumatised by this awful event until the day she died. It was her mother's adoptive parents' farm on which Oates grew up. "I feel such curiosity about my ancestors. They had so much courage," she says.

Oates was bullied at school ("it was just the sort of thing that kids do, it happens when you're small") and sexually molested ("again, that wasn't unusual, other girls were too"). When she was 14 her grandmother gave her a typewriter and she dashed off her first novel, which was rejected for being too depressing.

First published at 23, Oates was 31 when her early novel, them, dealing with corruption and race, won the National Book Award in America. She was rapidly inducted into the American Academy and Institute of Arts & Letters. Several of her novels have been filmed and the mesmerising We Were the Mulvaneys was an Oprah Winfrey Book Club choice.

The huge 939-page novel Blonde is her masterpiece, although The Falls, another epic family saga, published last year, is also a contender for that distinction. Blonde is a fictional account of the life of Norma Jeane Baker aka Marilyn Monroe, exploring the nightmare that is the American dream and the fallibility of its icons.

Unlike Norma Jeane, she's been blessed. "I've a wonderful career, marvellous students - they're so idealistic, so smart - and some good friends." The dearest of whom is her husband. Childless, they entertain so frequently because she finds cooking therapeutic.

Would she have written so much had they had children? "No, I don't think so, but then I was never strongly maternal. My brother also doesn't have children - it could be genetic, but it could be that I was so very interested in writing that I just didn't have time, although I do like children. My role models were childless - Virginia Woolf, Jane Austen, George Eliot, the Bronts."

Most days she runs. "The mind flies with the body," she claims. She races through the land and cityscapes of her fiction "like a ghost in a real setting". On days when Oates can't run, she isn't herself. "I can't recall a time when I wasn't running - and I can't recall a time when I wasn't writing."

Mother, Missing, by Joyce Carol Oates, is published by Fourth Estate, priced 17.99.